Electrical equipment



Filed Aug. 14, 1947 Wl'umm Koor 51h91) INVENTO@ fdl Patented June 13,1950 UNITED STATES PATENT OFFICE Application August 14, 1947, Serial No.768,533 In Great Britain May 20, 1947 3 Claims. (Cl. 321-57) Thisinvention relates to electrical equipment, and has for its chief objectto provide a method of, and apparatus for, producing substantially a twoor more phase current from a single phase supply without the necessityof using mechanically moving parts.

The method of producing a substantially two or more phase current from asingle phase supply according to the present invention in its broadestaspect comprises generating an alternating current ilux in a closed ironcircuit by means of a single phase supply, dividing the iiux into two ormore parts, varying the phase of the flux in one or more parts by meansof one or more shorted turns and utilising the two or more iiuXes toproduce two or more alternating currents of different phase.

'I'he apparatus for producing a substantially two or more phase currentfrom a single phase supply according to the present invention comprisesa laminated iron core defining at least two parallel closed magnetic uxpaths having a common portion, an input winding carried by that part ofthe core dening the common portion of the iiux paths, a shorted turndisposed about at least one of the other parts of the core deiining oneof the flux paths, and an output winding about said flux path.

The present invention is more particularly concerned with the productionof a substantially two-phase current from a single phase supply, inwhich case the output winding about that limb of the core which carriesthe shorted turn will produce a current, the phase of which is displacedfrom the phase of the input current, and the other current to producethe two-phase current may be obtained from a further output windingcarried. by the other limb of the core or from the input winding itself.

In order that this invention may be the more clearly understood andreadily carried into effect, reference may be made to the accompanyingdrawings, in which- Figure 1 illustrates diagrammatically the preferredmethod of producing a substantially twophase current from a single-phasesupply, and

Figure 2 illustrates a modification of the same.

Referring now to Figure 1 of the accompanying drawings, the apparatustherein illustrated ccmprises a laminated iron core I of the formnormally used in transformer construction, said core defining twoparallel magnetic flux paths II and I2 which have a common portion inthe centre limb of the core. An input winding Il carried by the centrelimb I3 is supplied with single-phase current and the magnetic flux setup in the centre limb will, by reason of the construction of the core,be divided into two parts and will flow in the iiux paths II and I2. Twooutput windings I5 and I6 are carried by the outer limbs II, I8 of thecore and, in the absence of any means affecting the magnetic uxesflowing in the paths Il and I2, the currents in the windings I5 and I6would be in phase with one another. If, however, we arrange a shortedturn I9 about, say, the limb I8, the phase of the magnetic flux withinthe output winding I6 will be varied and hence the phase of the currentflowing in the output winding I5 will diier from that flowing in theoutput winding I5.

By connecting up the windings I5 and I 6, as shown, we shall then have asubstantially twophase current produced from a single phase supplywithout the use of mechanically moving parts.

The degree of displacement of the phase angle of the current in thesecondary winding I6 will depend upon the construction and arrangementof the shorted turn I9, as will be well understood.

Given that by means of the shorted turn I9 it is possible to cause aphase displacement of the current in the winding I6, it will beappreciated that it is not necessary to use a separate output winding I5to produce the two-phase current. It is possible to tap off the secondphase from the primary or input winding I4, as at 20, whereupon, if weconnect up the windings as shown in Figure 2 of the drawings, we shallhave a substantially two-phase current, the phases being across theleads 2|, '22 and 22 and 23.

By means of the present invention it is also, if desired, possible toproduce a three or more phase current from a single-phase currentwithout the use of mechanically moving parts. Thus, for example, athree-phase current may be produced by having a laminated closed ironcore with four limbs defining three magnetic iiux paths having oneportion, i. e., the centre limb, common and by the use of two differentshorted turns on two of the limbs or by producing a two-phase currentfrom the current owing in the winding I5 or the winding I6 in the mannerdescribed above.

I claim:

1. Apparatus for producing a two phase current from a single-phasecurrent comprising a closed laminated iron core dening at least twoparallel closed magnetic flux paths having a common portion, an inputwinding carried by that 3 part of the core defining the common portionof the ux paths, a shorted turn disposed about one of the other parts 0fthe core dening one of the ux paths and an output winding about each ofthe said flux paths.

2. Apparatus for producing a two-phase current from a single-phasecurrent which comprises; a laminated closed-E-form iron core, an inputwindinga'carriedfby the centrelimbfof the core, anoutput Winding carried"by each ofthe outer limbs of the core, and a shorted turn about onelimb of the core, whereby the phase of th'e current flowing in theoutput Windingecarried by that limb will be varied with respect "tothephase of the current owingiinfltheibtherfoutput Winding, and the twooutput windings, when suitably combined, will producea'twoephasecurrent.

3. Apparatus for producing a two-phasecurrent from a single-phasecurrent which comprises; a laminated a:closedi-Eefomn @iron -core, fan`,input 4 Winding carried by the centre limb of the core. an outputwinding carried by each of the outer limbs of the core and a shortedturn on one limb of the core, whereby the phase of the current owing insaid. output winding is displaced from what it would otherwise be, saidoutput winding, when suitably connected up with the input winding, or aportion of the same, serving to produce a=tw`o=phase current from thesingle-'phase input.

WILLIAM KARTARSINGH.

REFERENCES CITED 'The1fo11owing references are of record in the file ofthis patent: Y

UNITED'STATES PATENTS "Number Y Name Date 732,204 Lunt June 30, 19031;"15'7.,'730 Spinelli Oct. 26, 1915 1,566,333 Lucas Dec. 22, 192523364558 Stocker Dec.4,.1944

